Union dyeing and printing of polyester/cellulose blends



United States Patent 3,413,074 UNION DYEING AND PRINTING 0F POLYESTER/ CELLULOSE BLENDS Albert Daniel Lowande, Middlesex, and Alfred Louis Cate, Somerset, N.J., assignors to American Cyanamid Company, Stamford, Conn., a corporation of Maine No Drawing. Filed Aug. 31, 1967, Ser. No. 664,617

4 Claims. (Cl. 8--21) ABSTRACT OF THE DISCLOSURE the fabric at a temperature of 380-435 F. for from seconds to 3 minutes. The dyed fabrics exhibit excellent fastness to washing as well as improved strength, brightness and fastness to light.

This invention relates to and has for its object the provision of an improved process for union dyeing or printing of polyester/cellulose blends and to a dye composition therefor.

More particularly, the invention relates to a process for union dyeing or printing of mixed or blended polyester and cellulose cloth or fabric. Thus, the fabric may be either blended at the yarn stage and subsequently woven into cloth or fabric, or not blended at the yarn stage but Woven together into a cloth or fabric.

The process of the present invention makes it possible to produce (1) a solid or union shade or (2) contrast effects on polyester/cellulose fabrics. Thus, the process does not leave one of the mixed fibers undyed, but dyes both fibers simultaneously.

In accordance with the process of the invention, there is used in the pad bath or print paste, a dye reactive with cellulose under acid conditions having at least one iminobispropionamide radical, an acid catalyst, a disperse dye, water and, optionally, a thickener.

More than one of either type of dye, i.e., disperse or fiber-reactive, may be present in the pad bath or print paste. In accordance with the process the aqueous bath or paste is padded or printed onto the fabric, the fabric is dried and the dry fabric heated at a temperature above 380 F., but below the melting point of the polyester, until maximum fixation of the dyes to the respective fibers has taken place. Any unfixed dye is then removed.

The process of this invention differs from previous methods in providing an improved continuous simultaneous method of union dyeing and printing fabrics composed of both polyester and cellulose. Together the two types of dyes, disperse and reactive, are applied to the cloth, together they are dried and together at the same temperature they are fixed, excess or unfixed or unreacted dye being removed. Weakly acid conditions persist as long as there is moisture present. Alkalinity at any point in the process is avoided until union dyeing or printing is complete. Thereafter optionally the fabric is washed or soaped to remove excess unfixed dyes. During the removal of excess dye, mild alkali may be present although even here the use of neutral soaps or surface active agents is the usual practice.

Heretofore, when combinations of disperse and reactive dyes have been used for the union dyeing of polyester/ cellulose blends, alkaline conditions have been used at that part of the process where fixation of the reactive dye to cellulose takes place. The fiber-reactive dyes used in the alkaline process of the art differ in structure from the dyes used in the process of this invention. Such prior art dyes may have, for instance, a monochloro or dichlorotriazine moiety (Procion M or A dyes). Such dyes need alkaline conditions for fixation to cellulose. Also, heating in the presence of alkali has an adverse effect on the union shade. Furthermore, disperse dyes tend to be unstable in alkali at high temperature. Also, in the presence of alkali, fiber-reactive dyes can react with a reactive hydrogen if present in the disperse dye. Thus, fixation to the cellulose is substituted by fixation to the disperse dye with resultant loss of color value on the fabric.

The process of this invention is advantageous in that the dyes are not applied with urea. In the mill in the large quantities needed, urea has been found to yellow and dull light shades. It also causes corrosion problems with copper fittings in the drying and heating steps.

The fiber-reactive dyes of the invention are a new class of fiber-reactive dyes characterized by the presence therein of a methylolated iminobispropionamide group which is attached to the dye moiety through a particular type of bridging group which has an electron-withdrawing effect by virtue of which the dyes may be applied to cellulose in the presence of an acid catalyst. These new dyes are disclosed and claimed in a copending application of Frank P. Lotfelman, Ser. No. 420,448, filed Dec. 22, 1964, now abandoned, and assigned to the assignee of the instant application. They conform to the formula:

RI CHZCHZC ON/ CHQOR RI CH2CH2CON R n where D is the residue of an organic dye moiety, Y is a bridging group selected from the group consisting of a covalent bond, sulfonyl, alkylenesulfonyl, alkyleneoxy, alkylenethio, carbonyl, alkylenecarbonyl and alkylene, the alkylene radicals in Y having 1-2 carbon atoms; R is a member selected from hydrogen and alkyl carbons; R is individually selected from the group consisting of hydrogen and the radical -CH OR and n is a positive integer less than three.

As shown in the copending application, the radical D can be the moiety of any organic dye, the novel and characterizing feature of the new dyes being the R! CH2CU2CON/ CHzOR RI CHzCHaC ON/ RI group. Numerous examples of the new class of dyes and their outstanding acid-fixing properties on cellulose are disclosed in the application Ser. No. 420,448.

The dyes fix over a wide range of temperatures, i.e., 300 F. to 435 E, which coincides with the range needed for the dyeing of polyesters, i.e., 380430 F. They react well under slightly acid conditions which are also good for the Thermosol dyeing polyesters. They do not react with the fiber under alkaline conditions and thus are distinct from known reactive dyes used in conjunction with disperse dyes in dyeing polyester/cotton blends.

The disperse dyes used in the present invention should be chosen especially for their fastness to sublimation and stability of hue to heat and pH. They should also have good fastness to light, washing and gas-fading. Examples of such disperse dyes are azo dyes of the phenylazopyrazolone series, as disclosed in U.S. 3,019,217 and 3,198,- 783, anthraquinone dyes containing a 2-(2-cyanoethoxy) ethoxy group, as disclosed in U.S. 3,264,325, substituted quinizarines, indandiones, substituted quinolines and the like. Suitable disperse dyes are those having a rating of 4-5 or 5 in Hot Pressing as shown in vol. I of the Colour Index, 2nd edition, pages 1655-1742. Under the acid fixation conditions of the process of this invention a stronger, brighter result is obtained in dyeing the disperse dye than under alkaline conditions of fixation.

The concentration of the acid catalyst, which fixes the fiber-reactive dye to the cellulose is important. It is, however, geared to the temperature and time of fixation rather than the concentration of the dye. The amount used is varied inversely to the temperature range of 380 F. to 435 F. Suitable acid catalysts are ammonium salts, such as the chloride, sulfate, phosphate and gluconate, hydrochlorides of mono-, diand triethanolamines and chlorides of magnesium. Also, Lewis acids, dilute mineral acids, organic acids, such as oxalic, malonic, adipic, acetic or lactic acids, and inorganic acids, such as fiuoroboric or fluosulfonic acid are suitable for the practice of this invention. The optimum catalyst concentration of ammonium chloride, a preferred acid catalyst, for example, is 4 grams per liter where the padded airdried fabric is heated in hot air at 350 F. for 1.5 minutes. When the temperature is 410 F., and the time 1.5 minutes, a concentration of 0.5 gram of ammonium chloride per liter is preferred.

A thickener may be used to adjust the viscosity and facilitate application of the pad bath or printing paste. Natural gums or resins or sodium alginate, about 2 g. per liter at pH 6-7, are preferred. The thickener also helps to prevent migration of the dyes on drying and subse-. quent heat treatment. In printing the thickener is increased or the water content reduced, or both.

I NaO s The padded fabric or print is then dried. Infrared predrying may be used followed by hot cylinder drying.

After drying, the fabric is heated (subjected to the action of heat) at 380-435 F. Either hot air may be used or actual contact with a hot roll or cylinder. Contact heat is faster and may even halve the amount of time needed for the heat treatment. In hot air, at 350 F., fixation of the fiber reactive dye is complete at 1.5 minutes, but at least 380 F. is needed for the polyester part of the union dyeing. At 410 F. the maximum fixation of the reactive dye takes place within 1.0 minute. This is an optimal temperature for dyeing of a disperse dye on polyester. The preferred temperature and time for hot air union dyeing in the process of this invention is 410 F. for 90 seconds. Excessive times such as five minutes cause appreciable tensile strength loss in the cellulose fiber.

After the heat treatment any excess dye not attached to the fabric is removed by washing or soaping. Soap- 4 ing is done in neutral soap or detergent solution at the boil. The fabric is rinsed, soaped and dried. The rinsing and soaping steps may be eliminated prior to resin finishing if this is done. However, the resin-finished fabric should then be soaped. Resin after-treatment may be desirable to improve fastness to perspiration and to drycleaning.

The resultant union-dyed fabric is characterized by excellent fastness to washing as well as improved strength, brightness and fastness to light.

When a fabric of polyester/cellulose blended yarn is union dyed using the process of this invention, it has no significant shade differences from face to back or sides to center.

When a fabric is woven with separate polyester and cellulose yarns, either union or patterned effects are possible, depending upon weave and the choice of hue of fiber-reactive and disperse dyes.

The components of the pad bath of the present invention may be present within the following concentration ranges.

Grams/liter Preferred Operable (a) Fiber reactive dye(s) 0 .1 0.001200 (b) Disperse dye(s) 0.1 80 0 001-200 (c) Acid cata1yst- 0.2510 0.1 35 (d) Thickener 2 -50 0 -l00 The following examples illustrate this invention.

EXAMPLE 1 Union pad dyeing of polyester/ cotton OH NH- II. Fiber Reactive Dye (Example 2, Ser. No. 420,448)

SOzN (CHzCHzC O NHCHZOIZDZ CH3 III. Disperse Dye (U.S. 3,264,325)

OCHzCH2OCH2CH2CN The solution is padded on a 50/50 polyester/cotton blend fabric, dried and cured at 410 F. for seconds in hot air. The union dyed fabric is then soaped off at F. for 3 minutes in a bath containing 0.06% tetra sodium pyrophosphate and 0.03% nonionic detergent which is a condensate of ethylene oxide with nonyl alcohol 9.5/1. The fabric is Washed and dried. It is dyed a uniform pink shade.

If 5 g. ammonium chloride is used with contact heat at 425 F., for 12 seconds, i.e., 6 seconds on each side, a similar result is obtained.

EXAMPLE 2 Continuous-union pad dyeing of polyester/cotton A pad bath is prepared by mixing, diluting and dissolving with hot water in a pail, Dyes I, II and III (of Example 1) in amounts of 1.5 lb., 0.375 lb. and 4.5 lb. paste, respectively.

The solution of dye is added to a tank containing fifty gallons water at 110 F.; 9.0 lb. solution of natural gums and 3.0 lb. ammonium chloride are added. The whole is diluted to 75 gal. with Water.

Five hundred yards of 50/50 polyester/ cotton are padded with this solution at a rate of 70 yards per minute, skyed, predried by infrared and dried by four hot roll cylinders at 180, 250, 250 and 350 F., respectively. The fabric is heat-treated for nine seconds by contact with ten rolls at 400-435 F.

Following this, the yardage is rinsed, soaped at 180 F., in water containing 1 lb./ 100 gallons of an anionic detergent, sodium N-methyl-N-oleyl taurate, rinsed and dried. The union-dyed fabric obtained is a medium pink shade. It is uniformly dyed with no shade differences from face to back or sides to center.

6 The procedure is the same as for Example 3. A full blue union shade is obtained of excellent fastness to washing.

EXAMPLE 6 Union printing of polyester/ cotton A print paste is made by mixing the dyes listed in Table I in the amounts shown with 75 grams of a sodium alginate emulsion prepared by homogenizing:

20 grams of sodium alginate granules stirred to a paste with 545 ml. water;

10 grams of a surfactant disodium N-octadecylsulfosuccinate, and

445 grams of a petroleum solvent distilling between 321 and 388 F.

TABLE I.PRINT FORMULATIONS IN GRAMS OF DYE PER 100 GRAMS PRINTING PASTE Fiber reactive dye Disperse dye 10% NH C1 Union shade solution on polyester] I II III III V VI in 1111. cotton 1. 00 l. 00 0. 00 2. 15 0. 012 0. 00 0. 5 Red. 0. 75 1. O0 0. 00 1. 50 0. 125 0.00 0. 5 Scarlet. 1. 00 6.00 0. 00 2. 20 1. 00 0. 00 0. 5 Orange. 0.00 2. 00 0. 00 0.00 0.50 0.00 0. 5 Yellow. 0. 00 2. 00 2. 00 0.00 0. 35 0.00 0. 5 Green. 0. 00 0. 00 2. 00 0. 00 0. 00 0. 00 0. 5 Turquoise. 0. 0. 00 l. 50 0. 25 0. 00 0. 00 0. 5 Blue. 1. 00 3.00 1. 50 1. 50 0. 0. 75 0. 5 Gray.

EXAMPLE 3 Red union dyeing of polyester/ cotton fabric A pad bath is made up having a concentration per liter of Grams Dye I of Example 1 20 Dye III of Example 1 Ammonium chloride 0.5 Sodium alginate 2 The bath is adjusted to pH 6.8 with dilute hydrochloric acid. A 65/35 polyester/cotton blended fabric is padded, dried and cured at 410 F. for 90 seconds. It is then rinsed and soaped.

A full blue-red union shade is obtained of excellent fastness to washing.

EXAMPLE 4 Yellow union dyeing of polyester/ cotton fabrics A pad bath is prepared as in Example 3, except that instead of Dyes I and II of Example 1, Dye II of Example l and a nitro dye of the formula:

are used in amounts of 20 g. powder and 30 g. double paste, respectively. Otherwise, the procedure of Example 3 is followed.

A full green-yellow union shade is obtained of excellent fastness to washing.

EXAMPLE 5 Blue union dyeings of polyester/ cotton fabric A pad bath is prepared, containing per liter Grams Dye IV of Example 6 16 Dye I of Example 1 I- 0.7 Dye III of Example 1 1.0

The prints obtained have good fastness to AATCC Tests Wash No. 2A, Acid Perspiration, Alkaline Perspiration, Dry C'rocking and Dry Cleaning.

The dyes of Table I are identified as follows:

Dyes I and II are Dyes I and II of Example 1.

Dye TV is a copper phthalocyanine dye of the structure:

(SOa )2 CuPo [SOMQ I SO N(OH CHzCONHCH2OH)2 2 Dye III is Dye III of Example 1. Dye V is:

wherein D is the residue of an organic dye moiety, Y is a bridging group selected from the group consisting of a covalent bond, sulfonyl, alkylenesulfonyl, alkyleneoxy, alkylenethio, carbonyl, alkylenecarbonyl and alkylene, the alkylene radicals in Y having 1-2 carbon atoms; R

is a member selected from hydrogen and alkyl of 1-4 carbons; R is individually selected from the group consisting of hydrogen and the radical CH OR and n is a positive integer less than three;

(b) a disperse dye having a rating of 4-5 or 5 in Hot Pressing as shown in the Colour Index, 2nd edition, vol. I, page 1655-1742;

(c) an acid catalyst, and (d) water, and

(2) drying the fabric at a temperature of 380-435 F.

for from 5 seconds to 3 minutes.

2. A process according to claim 1 in which the acid catalyst is ammonium chloride present in an amount of from 0.25 to 4.0 g. per liter.

3. A dye composition comprising:

(a) a fiber-reactive dye of the formula CHzCHzCON CHzOR CHzCHzCON wherein D is the residue of an organic dye moiety,

Y is a bridging group selected from "the group consisting of a covalent bond, sulfonyl, alkylene'sulfonyl, alkylenoxy, alkylenethio, carbonyl, alkylenecarbonyl and alkylene, the alkylene radicals in Y having 1-2 carbon atoms; R is a member selected from hydrogen and alkyl of 1-4 carbons; R is individually selected from the group consisting of hydrogen and the radical --CH OR and n is a positive integer less than three;

(b) a disperse dye having a rating of 4-5 or 5 in Hot Pressing as shown in the Colour Index, 2nd edition, vol. I, page 1655-1742;

(c) and acid catalyst; and

(d) water.

4. A dye composition according to claim 3, in which the acid catalyst is ammonium chloride present in an amount of from 0.25 to 4.0 g. per liter.

References Cited UNITED STATES PATENTS 4/1944 Dickey 260-199 XR 11/1962 Wedemeyer 817 XR FOREIGN PATENTS 12/1958 Great Britain.

OTHER REFERENCES Frick et al.: American Dyestufr Reporter, vol. 51, N0. 23, pp. 45-48.

NORMAN G. TORCHIN, Primary Examiner.

D. LEVY, Assistant Examiner. 

